“She took a short-circuit in the brain. She’s got problems,” CNN quoted Trump as saying on Saturday night at a campaign event in New Hampshire.
“Honestly, I don’t think she’s all there,” he added.
The Republican nominee has also dubbed Clinton “unstable”, “unbalanced” and “totally unhinged”, CNN reported.
The remarks were the latest attack from the Republican nominee at the end of a week in which he insulted the grieving parents of a Muslim American war hero, told a mother with a crying baby to leave one of his rallies and his polling numbers crashed with the campaign reaching “crisis” levels.
Trump went on to say about Clinton: “She’s a liar. She is a horrible, horrible human being.
“She’s incompetent and I don’t think that you can even think of allowing this woman to become President of the US,” CNN quoted Trump as saying.
Clinton’s use of the term “short-circuited” came as she answered a question on Friday at a gathering of black and Hispanic journalists about her claim that FBI Director James Comey said she had been “truthful” in discussing her use of a private email server during her time as Secretary of State.
“What I told the FBI, which he said was truthful, is consistent with what I have said publicly. I may have short-circuited, and for that, I will try to clarify,” she added.